Currently, disc brakes used by mine hoists, cars, high-speed trains, and the like each include three systems of a brake, a hydraulic and pneumatic station, and an electric control system. A belleville spring provides a positive pressure to brake pads, and the brake pads and a brake disc generate friction to implement brake. The operating principle is that the hydraulic and pneumatic station performs pressure relief for brake and pressurization for brake release. The system has the following problems. Deformation of the belleville spring (refer to FIG. 15 in the specification) causes a great change in an elastic force, the belleville spring has high requirements for the material, machining, and a heat treatment process, and it is inconvenient to monitor cracking of the belleville spring during operation. Because of the structure feature, a maximum positive pressure of a disc brake that has a belleville spring in a mine hoist and that is currently manufactured is 100000 N. The disc brake is manufactured by CITIC A hydraulic station system is complex, and the manufacturing costs are high. In addition, the hydraulic station cannot stop when a hoist or a high-speed train runs, a hydraulic pump cannot stop, and a motor performs useless work in most of the time. A drum hoist with a 5-m diameter manufactured by CITIC HIC is used as an example, there are 20 (10 pairs of) brake heads, and the manufacturing costs are greater than RMB 600000. The manufacturing costs of a hydraulic station are greater than RMB 600000, and energy consumed by a hydraulic pump motor is 4 kWh. The motor runs at day and night, increasing a load on a user, and wasting resources. For a disc brake used for a heavy duty truck, a maximum brake torque is no greater than 10000 N*m, but the maximum brake torque of a Lin-Xie brake in a same size may be 30000 N*m.
In the Lin-Xie brake of the present invention, a high-pressure nitrogen cylinder provides a positive pressure to brake pads. The high-pressure nitrogen cylinder may be conveniently manufactured. A piston displacement of the nitrogen cylinder has a small effect on a change of an elastic force (refer to FIG. 15 in this specification). Only injection of nitrogen pressure needs to be conveniently changed, the positive pressure may be precisely provided to the brake pads. The high-pressure nitrogen cylinder is used as a gas spring, and has low requirements for the material and processing techniques. An operating pressure of an oil seal is not greater than 8 MPa. Usually, an allowable operating pressure of the oil seal is up to 38 MPa. An operating pressure of the oil seal in the Lin-Xie brake is far less than 38 MPa, and the oil seal has a short stroke and a slow speed, to ensure that the oil seal is used for a long period of time. The oil seal only needs to be replaced regularly (more than five years), and the nitrogen cylinder has only one air inlet passage and is provided with a one-way valve. Even though an air inlet pipe and associated bolts and nuts are removed, it can still be ensured that the high-pressure nitrogen in the nitrogen cylinder does not leak, and the brake pads are always provided with a preset positive pressure to implement brake at any time. Even though the high-pressure nitrogen leaks during operation, first, a nitrogen cylinder is provided to supplement nitrogen, to provide a positive pressure in a considerably long period of time except that loss of the pressure suddenly occurs because of extreme conditions such as fires and explosions (the belleville spring is also ineffective in this case). Second, an instrument is provided to facilitate monitoring, to process the nitrogen leakage in a timely manner. However, the belleville spring may suddenly crack. Therefore, when the high-pressure nitrogen cylinder is used as a gas spring, the reliability of the high-pressure nitrogen cylinder is undoubtedly greater than the reliability of the belleville spring.
In view of the features of the high-pressure nitrogen cylinder, for a mine hoist, only a Lin-Xie brake of one specification and one size needs to be manufactured to replace all belleville spring brakes. Currently, belleville spring brakes have multiple specifications, and their positive pressure is from 10000 N to 100000 N. For example, an inner diameter of a working cylinder of a Lin-Xie brake used by a hoist is 200 mm. A pressure of nitrogen stored in a nitrogen cylinder is usually 12 MPa, and an allowable pressure is from 0 MPa to 8 MPa. A positive pressure of 200*200*3.14±4*(0−8)=0−251200 N may be generated to be applied to brake pads. Only a hydraulic fluid pipe connector provided with a damper hole is not universal. In addition, pressure changes of the nitrogen cylinder can be conveniently monitored. An oil-gas linkage plunger pump is used to provide power for brake or release of the brake pads, to replace the hydraulic station. Compressed air used by the Lin-Xie brake of the present invention may be directly connected to a pipeline of an air compression station of a mine, a car, or a high-speed train. Alternatively, an air compressor may be provided. Because the air compressor is provided with an air container, a motor of the air compressor does not need to continuously run, to reduce energy consumption. Costs of the air compressor are less than one tenth of costs of the hydraulic station.
For an original hoist using belleville spring brakes, because a deformation of a belleville spring brake is low, the belleville spring brakes only can be separately fixed on a base and have no servo effect. Therefore, a requirement on end face runout of a brake disc of a hoist drum is high, and a requirement on installation of the base is also high. However, for the Lin-Xie brake of the present invention, a floating support used to support a brake head has a servo effect. Therefore, a requirement on end face runout of a brake disc is low, and a requirement on installation of a base is also low. Therefore, the Lin-Xie brake of the present invention is an ideal product to replace the original belleville spring brake.